The present invention relates generally to the production of gaseous hydrogen with carbonous materials in the presence of steam by the steam-carbon reaction, and more particularly to such generation of hydrogen by rapidly comminuting coal in the presence of high-temperature steam.
Gaseous hydrogen is becoming of increasing interest as a fuel, as feed stock in the production of various chemicals and propellents, and for use in coal liquefaction reactions. The production of hydrogen can be accomplished by employing several different techniques such as by the disassociation of water, reforming of methane, and by practicing the well known steam-carbon reaction where in the presence of relatively high temperatures carbon and steam react to produce carbon dioxide and gaseous hydrogen. The practice of the steam-carbon reaction is particularly successful with low rank coal such as lignite or subbituminous coal due to the greater inherent reactivity of these low rank coals. Further, lignite or subbituminous coal have higher concentrations of active sites, higher porosity, and a more uniform distribution of alkaline impurities which act as a catalyst. These coals when contacted with steam produce hydrogen with the greater concentration of hydrogen occurring with higher steam temperatures.